Muffler



H. S. POWELL Jan. 4, 1938.

MUFFLER 7 Filed May 1, 1936 2 Sheets-Sheet 1 glizX Jan, 4, 1938.

H. S. POWELL MUFFLER Filed May 1, 1956 2 Sheets-Sheet 2 Patented Jan. 4, 1938 UNITED STATES moans iFATENT OFFiCE 6 Claims.

The present invention relates to new and useful improvements in mufflers of the type used for silencing the exhaust from an internal combustion engine.

An object of the present invention is to provide a muffler of the above type wherein the casing is divided into a plurality of intermediate compartments through which inlet, return and outlet tubes extend, and wherein each of the compart- 10 ments is in communication with a separate tube. A further object of the invention is to provide a mufller of the above type wherein a spirally wound portion of each tube affords communication with a single corresponding compartment.

A still further object of the invention is to provide a muffler of the above type wherein the communicating portion of each tube is formed by a spirally wound sheet which is effectively prevented from vibrating or rattling.

A still further object of the invention is to provide a muffler of the above type wherein there is afforded a simple and strong construction which is easy to manufacture and which is readily assembled.

5 The above and other objects of the invention will in part be obvious and will be hereinafter more fully described.

In the drawings:

Fig. l is a side view in section showing the 3 assembled muffler.

Fig. 2 is an end view in section taken along the line 2--2 of Fig. 1.

Fig. 3 is a detail diagrammatic view showing the plate from which the spiral tube is formed.

Fig. l is a view showing the plate folded upon itself.

Fig. 5 is an enlarged perspective view showing the spirally wound portion of each tube.

The invention relates generally to a muffler .p) for silencing the exhaust gases issuing from an internal combustion engine and includes a casing which is provided with expansion chambers at the ends thereof and a plurality of intermediate chambers or compartments which serve 45 as resonant chambers. Extending through each of the intermediate compartments are a plurality of tubes through which the exhaust gases are adapted to pass. Each intermediate compartment is in communication with a different so tube and with only that tube so that, in this manner a resonant chamber for each tube is provided. A spiral tube in the form of a spirally wound sheet formed as a portion of each tube provides a passage for the gases between a com- 55 municating compartment and tube. This spirally wound sheet or plate may be solid or it may be provided with apertures. In either case, a portion of the gases passing through a tube will be directed around the tortuous path provided by the spirally wound section from the tube into the communicating compartment and then, after expansion, back into the same tube for further passage through the casing.

Referring more in detail to the accompanying drawings, an outer casing iii is illustrated as being oval in shape and having the ends thereof closed by heads or end members ll, l2. A plurality of spaced intermediate partition walls l3, I4, !5, it are each provided with flanges H which are suitably secured to the outer casing l0. These partition walls divide the internal space of the easing into a plurality of intermediate compartments A, B, C. The partition walls is and 56 are spaced from the heads ll, [2 respectively so as to provide expansion chambers D, E.

An inlet tube l8 extends through the head it and the chamber D and thence through each of the intermediate partition walls and opens into the expansion chamber E at the outlet end of the casing. The intermediate partition walls are provided with additional flanges l9 which are suitably secured around a tube Hi. In the illustrated embodiment of the invention, it will be seen that the inlet tube i8 is made up in sections Ilia and I8!) which are connected between the partition walls i3 and M by a spiral tube section 2!) which will be hereinafter more fully described. A return tube 2! extends between the end expansion chambers D and E and is made up of sections 2 id, 211) which are joined between the partition walls I4, l5 by a similar spiral tube section 26a. An outlet tube 22 extends from the expansion chamber D at the inlet end of the casing l0 through the intermediate partition walls and out through the head 2 at the opposite end of the casing. This outlet tube is also made up of sections 22a, 22b which are joined between the intermediate partition walls l5, [6 by a similar spiral tube 201).

Referring to Figs. 3, 4 and 5, each of the spiral tube sections 20, 26a, 2% is formed from a metal sheet 23 which is bent upon itself, as shown in Fig. 4, and then spirally wound into the completed form shown in Fig. 5. The sheet 23 is provided with a plurality of spaced projections in the form of bosses 24 arranged in groups which extend from opposite sides of the sheet 23. These bosses 24 serve as spacers when the sheet is folded upon itself as shown in Fig. 4, and when the folded sheet is wound upon itself to complete the spiral tube, as shown in Fig. 5. Thus the Cal overlapping layers of the spiral tube are spaced apart and are prevented from vibrating or rattling. As stated above, the spirally wound sheet may be solid or provided with apertures 25 as shown in the drawings. The outer edges 23a, 23b of the spirally wound sheets are suitably fitted and secured within the edges of the tube sections which are joined thereby.

If imperforate spiral tubes are employed, a portion of the gases passing therethrough will be directed around the spiral passages formed between the overlying layers of the sheet into the particular intermediate compartment with which communication is afforded. If, however, a perforated sheet is employed, a portion of the gases will gain access to the particular communicating compartment through the perforations therein.

The exhaust gases entering the casing l0 through the inlet tube 18 will be directed through the spiral tube 28 which joins the sections [8a, [81) thereof. A portion of the gases passing through the spiral tube 29 will gain access to the compartment A and, after expansion therein, will return to the tube l8 and pass into the expansion chamber E. The gases will then flow from the expansion chamber E to the return tube a and a portion or" the gases passing through the connecting spiral tube 29a will flow into the intermediate compartment B and then back into the tube and on to the expansion chamber D at the inlet end of the casing. From the expansion chamber D, the gases will flow through the outlet tube 22 and a portion of the gases passing through the spiral tube 20a will flow into the compartment C and then back to the tube 22 and out through the head l2.

From the foregoing description it will be seen that each tube communicates with one and only one intermediate compartment and that, each compartment is in communication with a different tube so that a closed resonant chamber is pro vided for the gases passing through each of the tubes. The provision of the spirally wound tube sections which aiiord communication between the proper tube and compartment also serve to dampen or restrict to a certain extent the passage of the exhaust gases through the mufiler.

It is to be clearly understood that minor changes in the details of construction and arrangement of parts may be made without departing from the scope of the invention as set forth in the appended claims.

I claim:

1. A mufiler comprising a casing having walls and partitions dividing the internal space of the easing into a plurality of separate compartments, and a plurality of tubes extending through said compartments for directing the exhaust gases through the casing, each of said tubes having a portion thereof formed by a spirally wound section for providing communication between each compartment and a different tube.

2. A mufiler comprising a casing having walls and partitions dividing the internal space of the easing into a plurality of separate compartments, inlet and outlet tubes extending through said compartments, and a return tube extending through said compartments and establishing communication between the inlet and outlet tubes, each of said tubes having a portion thereof formed by a spirally wound section for establishing communication between each of said compartments and a different tube.

3. A muflier comprising a casing having walls and partitions dividing the internal space of the casing into end expansion chambers and a plurality of intermediate compartments, an inlet tube extending through said compartments and communicating with the expansion chamber at the outlet end of said casing, an outlet tube extending through said compartments and communicating with the expansion chamber at the inlet end of said casing, a return tube extending through said compartments and communicating with both said expansion chambers, each of said tubes having a portion thereof formed by a spirally wound section for establishing communication between each tube and a difierent compartment.

4. A muiller comprising a casing having walls and partitions dividing the internal space in the casing into a plurality of separate compartments, and a plurality of tubes extending through said compartments for directing the exhaust gases through the casing, each of said tubes having a portion thereof formed by a spirally wound sheet having a plurality of projections thereon for spacing apart the overlapping portions of the sheet, said spirally wound sheets providing communication between each compartment and a diiferent tube.

5. A muffler comprising a casing having walls A and partitions dividing the internal space in the casing into a plurality of separate compartments, and a plurality of tubes extending through said compartments and directing the exhaust gases through the casing, each of said tubes having a section thereof formed by a double wall spirally wound sheet for providing communication between each compartment and a different tube.

6. A mufiler comprising a casing having walls and partitions dividing the internal space in the casing into a plurality of separate compartments, a plurality of tubes extending through said conipartments and directing the exhaustgases through the casing, each of said tubes having a section thereof formed by a double wall spirally wound sheet for providing communication between each compartment and a different tube, and spaced projections on the walls of said sheet contacting with the adjacent wall for preventing vibration thereof.

HERBERT S. POWELL. 

